AN IMPORTANT STEP IN BATTLE AGAINST ENDOPHTHALMITIS

A long- awaited commercial singledose preparation of cefuroxime for intracameral injection after surgery has become available in several European countries and looks set to be launched throughout most of Europe very soon. The new formulation is called AprokamR (Laboratories Thea) and is provided in a vial that contains 50mg anhydrous cefuroxime powder which can be reconstituted with saline solution in a single dilution. it therefore reduces of the chances of batch contamination and dilution errors that can occur with so-called kitchen pharmacy. “The launch of Aprokam unequivocally represents an important step in the battle against endophthalmitis, it also represents the achievement of one of the EsCRs Endophthalmitis study Group's principal objectives, said Peter Barry FRCs, Dublin ireland, who chaired the ESCRS Endophthalmitis study.

“The ESCRS study was designed to prove the efficacy and safety of intracameral cefuroxime in a randomised trial. But then having done that, we wanted to encourage industry to come up with an approved commercial product to overcome everyone's anxiety about the risks of using an unapproved product,†he told EuroTimes.  In the ESCRS study, patients who received intracameral cefuroxime at the conclusion of cataract surgery had a fivefold reduction in the rate of postoperative endophthalmitis compared to those who did not receive the antibiotic (0.05 per cent vs 0.35 per cent) (Barry et al, J Cataract Refract Surg. 2006 Mar;32(3):396-406). Many centres of the world have since that time adopted the use of intracameral cefuroxime in their cataract surgeries and have reported similar reductions in their rates of endophthalmitis. however, there are many surgeons who are unwilling to use an off-label product and there are many who have criticised the kitchen pharmacy method of preparation, which could itself lead to dilution errors and outbreaks of endophthalmitis from contamination.

Easier preparation

At present in most countries cefuroxime is prepared for intracameral use in hospital pharmacies or in the operating theatre and requires two dilutions, instead of just one dilution as in the case of Aprokam. Moreover, since cefuroxime is often prepared in batches for later use, one case of contamination or one dilution error can affect multiple patients. “The big problems with cefuroxime have been that you need to carry out two dilutions from one bottle, and from that, prepare five syringes and that would last one week. All of this requires a lot of organisation and quality monitoring of the storage organisation,†said Beatrice Cochener MD, ChU Brest, Brest, France. There have been reports in the literature of dilution errors and batch contamination. in one hospital an incorrect dilution resulted in a series of patients receiving intracameral cefuroxime at 10 times its recommended concentration. At another hospital, a contaminated batch of diluted cefuroxime resulted in eight patients developing fungal endophthalmitis. Preparing Aprokam involves the injection 5.0ml of 0.9 per cent sodium chloride solution into the vial containing cefuroxime with a sterile needle, then shaking the vial until the solution is free of particles. The next step is to aspire at least 0.1ml of the solution into a 1.0ml syringe then replacing the needle with an anterior chamber cannula and expelling all the air from the syringe. sterile technique is necessary throughout the reconstruction procedure and the vial and all the remaining solution in the vial must be discarded. “Aprokam gives us the security of being obtained in an approved formulation directly from the manufacturer, it also saves time because it only requires one reconstruction. There is also the added safety of having one vial for one patient,†Dr Cochener noted.

Good track record

The inspiration behind the EsCRs Endophthalmitis study was the findings obtained from the swedish cataract surgery registry. The registry records nearly all cases of cataract surgery performed in sweden and an analysis by Per Montan MD showed that the incidence of endophthalmitis fell dramatically following the adoption of intracameral cefuroxime by most surgeons in 1998. The incidence of endophthalmitis remains very low in sweden with the latest registry showing an incidence of just below 0.02 per cent. “When a few clinics first started using it word quickly spread that it appeared to be effective in reducing endophthalmitis rates, so essentially all clinics in sweden have been using this regimen for many years now,†said Anders Behndig MD, Umea University, Umea, sweden. he noted that the numbers of endophthalmitis cases caused by strains resistant to intracameral cefuroxime have not increased in sweden over the years. Moreover, the resistant species were those that had already been resistant to cefuroxime. There is no indication that species sensitive to the antibiotic are developing a resistance to it. in addition, endophthalmitis rates have continued to decline in a slow but sure fashion. That has probably been due to improvements in surgery, such as smaller incisions, shorter operating times and the fact that patients now undergo cataract surgery in sweden at a younger age than they used to. he noted that once it has been approved cataract surgeons in sweden will adopt the use of Aprokam for its safety advantage and approved status. Eye surgeons in sweden currently use cefuroxime in surgeries involving the anterior segment, including glaucoma surgery, penetrating and posterior lamellar transplants and vitrectomy, when combined with cataract surgery. Jorge Alio MD PhD, Vissum, Alicante, spain, a member of the EsCRs Endophthalmitis study Group, noted that the incidence of endophthalmitis among patients in the study at his centre who received intracameral cefuroxime had the same low incidence of endophthalmitis. Another centre in spain has reported similar reductions in the rate of the complication when patients received the intracameral antibiotic. “The great reductions in endophthalmitis in many centres around the world after the introduction of intracameral cefuroxime is something that should be acknowledged. But up to now all the cefuroxime preparations have been off-label, so Thea deserves congratulation for providing a better way of using prophylactic antibiotics,†he told EuroTimes.